Solid-state imaging device and electronic apparatus

ABSTRACT

A solid-state imaging device which includes, a photoelectric conversion film provided on a second surface side which is the opposite side to a first surface on which a wiring layer of a semiconductor substrate is formed, performs photoelectric conversion with respect to light in a predetermined wavelength region, and transmits light in other wavelength regions; and a photoelectric conversion layer which is provided in the semiconductor substrate, and performs the photoelectric conversion with respect to light in other wavelength regions which has transmitted the photoelectric conversion film, in which input light is incident from the second surface side with respect to the photoelectric conversion film and the photoelectric conversion layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/527,221, filed Oct. 29, 2014, which is a continuation of U.S. patentapplication Ser. No. 13/456,418, filed Apr. 26, 2012, now U.S. Pat. No.8,907,262, which claims priority to Japanese Patent Application No. JP2011-105284, filed in the Japan Patent Office on May 10, 2011, theentire disclosures of which are hereby incorporated herein by reference.

BACKGROUND

The present disclosure relates to a solid-state imaging device and anelectronic apparatus, particularly, to an electronic apparatus whichperforms photoelectric conversion to input light using a photoelectricconversion film, and an electronic apparatus having the solid-stateimaging device.

As the solid-state imaging device, a device is in general use in which,for example, pixels (sub-pixels) corresponding to three primary colorsof R (red), G (green), and B (blue) are arranged planarly on thesemiconductor substrate, light beams of the three primary colors arephotoelectrically converted, respectively in each pixel, and the chargeobtained by the photoelectric conversion is read out. As the pixel arrayof colors, the Bayer array in which one red pixel and one blue pixel arepresent with respect to two green pixels is representativelyexemplified.

In this type of solid-state imaging device, there is a problem in thatcolor separation occurs, since the light beams of the three primarycolors RGB are detected in different plane positions from each other,and a false color occurs due to the difference in light receivingposition. The false color causes a deterioration of image quality. Inorder to avoid this problem, a solid-state imaging device having aso-called lamination type pixel structure in the related art, in which Glight photoelectric conversion film is provided outside thesemiconductor substrate, and photoelectric conversion layers for B lightand R light are provided inside the semiconductor substrate has beenproposed (for example, refer to Japanese Unexamined Patent ApplicationPublication No. 2006-278446).

SUMMARY

The solid-state imaging device having the lamination type pixelstructure in Japanese Unexamined Patent Application Publication No.2006-278446 adopts a front surface side illumination pixel structure inwhich input light is radiated from the front surface side of thesemiconductor substrate with respect to the pixel, when a surface on aside where a wiring layer of the semiconductor substrate is formed isset to the front surface. In a case of the front side illumination pixelstructure, since a wiring layer is present between the substrate surfaceand a photoelectric conversion film which is arranged thereon, there isa distance between the photoelectric conversion layer provided insidethe semiconductor substrate and the photoelectric conversion filmprovided outside the semiconductor substrate.

Here, a case where light is obliquely input to the pixel is assumed.Since the G light photoelectric conversion film is present in thevicinity of the input face, the input light can be photoelectricallyconverted regardless of the angle of light which is input obliquely. Onthe other hand, since the photoelectric conversion layers for B lightand R light which are provided inside the semiconductor substrate arepresent at a position separated from the G light photoelectricconversion film, the larger the inclination angle, the more difficult itis for input light to reach the photoelectric conversion layer. That is,a change in sensitivity with respect to F value is different dependingon the arrangement position of the photoelectric conversion film and thephotoelectric conversion layer. Due to this, F value dependency insensitivity occurs in each color.

Therefore, in the present disclosure, it is desirable to provide asolid-state imaging device which is able to reduce an F value dependencyfor the sensitivity of each color when adopting a lamination type pixelstructure, and an electronic apparatus including the solid-state imagingdevice.

According to an embodiment of the present disclosure, there is provideda solid-state imaging device which includes, a photoelectric conversionfilm which is provided on a second surface side which is opposite to afirst surface on which a wiring layer of the semiconductor substrate isformed, which performs photoelectrical conversion with respect to lightwith a predetermined wavelength region, and transmits light with anotherwavelength region; and a photoelectric conversion layer which isprovided inside the semiconductor substrate, and performsphotoelectrical conversion with respect to the light in anotherwavelength region which has transmitted the photoelectric conversionfilm, in which the solid-state imaging device has a configuration inwhich input light is incident from the second surface side with respectto the photoelectric conversion film and the photoelectric conversionlayer. The solid-state imaging device is used as an imaging unit (imagereading unit) of a variety of electronic apparatuses.

According to the embodiment of the present disclosure, in thesolid-state imaging device, or the electronic apparatus which has thesolid-state imaging device as the imaging unit, in a case where inputlight is incident from a second surface side when a first surface onwhich a wiring layer of the semiconductor substrate is formed is set toa substrate surface, it is a so-called backside illumination pixelstructure in which the input light is radiated from a rear surface sidewith respect to the photoelectric conversion film and the photoelectricconversion layer.

The backside illumination pixel structure is a structure in which thewiring layer is not present between the semiconductor substrate and thephotoelectric conversion film, accordingly, it is possible to make thedistance between the photoelectric conversion film and the substratesurface, and the distance between the photoelectric conversion film andthe photoelectric conversion layer in the substrate, compared to astructure in which the wiring layer is present, that is, a so-calledfront side illumination pixel structure. Due to this, it is possible toreduce a change in sensitivity with respect to the F value which iscaused by a difference in arrangement position of the photoelectricconversion film and the photoelectric conversion layer in the opticalaxis direction of the input light.

According to the present disclosure, it is possible to reduce the Fvalue dependency for the sensitivity of each color, since the change insensitivity with respect to the F value which is caused by a differencein arrangement position of the photoelectric conversion film and thephotoelectric conversion layer in the optical axis direction of theinput light can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view which shows a pixel structure accordingto a first example of a solid-state imaging device according to thepresent disclosure.

FIG. 2 is a top view which shows a state where a light shielding film ofa pixel array unit in the pixel structure according to the firstexample.

FIG. 3 is an enlarged view of four pixels in FIG. 2 which are adjacentto each other vertically, and horizontally.

FIG. 4 is a plan view which shows a state where transparent electrodesare added to the upper electrode in a laminating manner in the pixelstructure according to the first example.

FIGS. 5A and 5B are process diagrams (first thereof) which describemanufacturing processes of the pixel structure according to the firstexample.

FIGS. 6A and 6B are process diagrams (second thereof) which describemanufacturing processes of the pixel structure according to the firstexample.

FIGS. 7A and 7B are process diagrams (third thereof) which describemanufacturing processes of the pixel structure according to the firstexample.

FIGS. 8A and 8B are process diagrams (fourth thereof) which describemanufacturing processes of the pixel structure according to the firstexample.

FIG. 9 is a process diagram (fifth thereof) which describes amanufacturing process of the pixel structure according to the firstexample.

FIG. 10 is a process diagram (sixth thereof) which describes amanufacturing process of the pixel structure according to the firstexample.

FIG. 11 is a process diagram (seventh thereof) which describes amanufacturing process of the pixel structure according to the firstexample.

FIG. 12 is a top view which shows a state where a light shielding filmof a pixel array unit is formed in a pixel structure according to asecond example.

FIG. 13 is an enlarged view of four pixels in FIG. 12 which are adjacentto each other vertically, and horizontally.

FIG. 14 is a plan view which shows a state where transparent electrodesare added in a laminating manner on upper electrodes in the pixelstructure according to the second example.

FIG. 15 is a top view which shows a state where a light shielding filmof a pixel array unit is formed in a pixel structure according to athird example.

FIG. 16 is an enlarged view of four pixels in FIG. 15 which are adjacentto each other vertically, and horizontally.

FIG. 17 is a plan view which shows a state where transparent electrodesare added in a laminating manner on upper electrodes in the pixelstructure according to the third example.

FIG. 18 is a cross-sectional view which shows a pixel structureaccording to a fourth example.

FIG. 19 is a block diagram which shows an example of a configuration ofthe electronic apparatus according to the present disclosure, forexample, an imaging device.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments for performing a technology of the presentdisclosure (hereinafter, referred to as “embodiment”) will be describedin detail with reference to drawings. In addition, the description willbe made in the following order.

1. Description of embodiments

1-1. First example

1-2. Second example

1-3. Third example

1-4. Fourth example

2. Modification example

3. Electronic apparatus (Imaging device)

4. Configuration of the present disclosure

1. Description of Embodiments

The solid-state imaging device according to embodiments of the presentdisclosure adopts a lamination-type pixel structure in which aphotoelectric conversion film which performs photoelectrical conversionwith respect to light in a predetermined wavelength region, andtransmits light in another wavelength region is provided outside asemiconductor substrate, and a photoelectric conversion layer whichperforms the photoelectrical conversion with respect to light which hastransmitted the photoelectric conversion film, and is in anotherwavelength region is provided inside the semiconductor substrate.

In this lamination-type pixel structure, the photoelectric conversionfilm which is provided outside the semiconductor substrate absorbs lightin a predetermined wavelength region which is included in input light,for example, G (green) light, and performs photoelectrical conversionwith respect to the G light. On the other hand, the photoelectricconversion layer which is provided inside the semiconductor substrate isformed of, for example, two photoelectric conversion layers which arevertically provided in the optical axis direction of the input light.Specifically, one of the two photoelectric conversion layers is locatedat a position on the surface layer side of the semiconductor substrate,and the other photoelectric conversion layer is located at the lowerpart of the one photoelectric conversion layer.

In addition, the photoelectric conversion layer which is located at theposition on the surface layer side of the semiconductor substratebetween the two photoelectric conversion layers absorbs light other thanG light which has transmitted the photoelectric conversion film, in thelight in the wavelength range, for example, B (blue) light, and performsthe photoelectric conversion with respect to the B light. In addition,the photoelectric conversion layer which is located at the lower part ofthe photoelectric conversion layer on the surface layer side absorbslight which has transmitted the photoelectric conversion layer on thesurface layer side, for example, R (red) light, and performs thephotoelectric conversion with respect to the R light.

Here, when the first surface on which a wiring layer of thesemiconductor substrate is formed is set to the front surface of thesubstrate, the G light photoelectric conversion film is provided on thesecond surface side, that is, the rear surface side of the substrate. Inaddition, as a structure in which the input light is radiated (incident)to the G light photoelectric conversion film, a backside illuminationpixel structure in which the input light is radiated from the rearsurface side is adopted.

In this manner, in the lamination-type pixel structure in which thebackside illumination is adopted, since the wiring layer is not presentbetween the semiconductor substrate and the G light photoelectricconversion film, it is possible to make the distance short between thephotoelectric conversion film and the substrate surface, and between thephotoelectric conversion film and the photoelectric conversion layerinside the substrate compared to the pixel structure of the front sideillumination on which the wiring layer is present. Due to this, it ispossible to reduce the F value dependency for the sensitivity of eachcolor, since the change in sensitivity with respect to the F value whichis caused by a difference in arrangement position of the photoelectricconversion film and the photoelectric conversion layer in the opticalaxis direction of the input light can be reduced.

In addition, since only single color information is obtained from eachpixel (sub pixel) in the solid-state imaging device of, for example, aBayer array, insufficient color information is complemented bycollecting and supplying color information from peripheral pixelsthereof with respect to each pixel, by performing signal processingwhich is referred to as demosaicing. However, when performing suchsignal processing, as described above, a deterioration of image qualitywhich is referred to as a false color is caused accompanying the signalprocessing. Such a problem can be settled by adopting the abovedescribed lamination-type pixel structure.

Hereinafter, a detailed example of the solid-state imaging deviceaccording to the embodiment of the present disclosure will be describedas the first to fourth examples. Hereinafter, a pixel structure of aunit pixel (one pixel unit) including the photoelectric conversion filmand the photoelectric conversion layer as features of the embodimentwill be mainly described.

1-1. First Example

First, a configuration of a pixel structure and a manufacturing processaccording to a first example of a solid-state imaging device accordingto the embodiment of the present disclosure will be described.

Configuration of Pixel Structure

FIG. 1 is a cross-sectional view of a pixel structure according to thefirst example of the solid-state imaging device according to theembodiment of the present disclosure.

In FIG. 1, the semiconductor substrate, for example, a silicon substrate11 sets a lower surface 11 _(A) to the front surface (first surface),and an upper surface 11 _(B) on the opposite side thereof to the rearsurface (second surface). A wiring layer is formed on the front surface11 _(A) side of the silicon substrate 11. Here, for simplifying thedrawing, the wiring layer is not shown in the drawing.

For example, B (blue) light photoelectric conversion layer 12 isprovided in the surface layer of the rear surface 11 _(B) side insidethe silicon substrate 11. The B light photoelectric conversion layer 12is formed such that, for example, the cross-section thereof has aninverted L shape, performs photoelectric conversion with respect to theB light included in the input light, and accumulates charges generateddue to the photoelectric conversion.

Specifically, in the inverted L shape photoelectric conversion layer 12,a portion parallel to the substrate surface becomes the photoelectricconversion unit 12 _(A), and a portion which is vertical to thesubstrate surface becomes the photoelectric conversion unit 12 _(B). Afloating diffusion unit 13 (hereinafter, described to as “FD unit”) isprovided in the vicinity of the B light photoelectric conversion layer12, and the charge in the photoelectric conversion layer 12 istransferred to the FD unit 13 by a control of a transfer gate 14 whichis formed in the wiring layer.

For example, an R (red) light photoelectric conversion layer 15 isprovided on the lower part of the B light photoelectric conversion layer12. The R light photoelectric conversion layer 15 performs thephotoelectric conversion with respect to the R light which is includedin the input light, and accumulates charges which are generated due tothe photoelectric conversion. Here, the FD unit is provided in thevicinity of the R light photoelectric conversion layer 15, as well,though it is omitted in the drawing, and the charge in the photoelectricconversion layer 15 is transferred to the FD unit by a control of thetransfer gate which is formed in the wiring layer.

For example, a G (green) light charge accumulation unit 16 is providednext to the photoelectric conversion layers 12 and 15. The chargeaccumulation unit 16 is provided outside the silicon substrate 11, andaccumulates the charge obtained due to the photoelectric conversion by aG light photoelectric conversion film 17, which is described later. AnFD unit 19 is provided in the vicinity of the charge accumulation unit16, and charges in the charge accumulation unit 16 are transferred tothe FD unit 19 by a control of a transfer gate 20 which is formed in thewiring layer.

In addition, an overflow barrier (OFB) 20 for washing out charges whichoverflow from the charge accumulation unit 16 is provided on the chargeaccumulation unit 16. In addition, a contact unit 21 is formed betweenthe overflow barrier 20 and the substrate surface, for example, by an N⁺diffusion region. The charge which is obtained due to the photoelectricconversion by the G light photoelectric conversion film 17 istransferred to the charge accumulation unit 16 through the N+ contactunit 21 and the overflow barrier 20.

The above described B light photoelectric conversion layer 12, R lightphotoelectric conversion layer 15, the G light charge accumulation unit16, and constituent elements which are incorporated thereto is providedas unit pixels.

An anti-reflection film 22 is formed on the rear surface of the siliconsubstrate 11 over the entire substrate surface. A contact hole 23 isformed in a state of being reached the substrate surface of the siliconsubstrate 11 on the anti-reflection film 22. In addition, lightshielding films 24 (24 _(A) and 24 _(B)) which define a region wherelight is input to the silicon substrate 11 are formed on theanti-reflection film 22. The light shielding films 24 mainly have afunction of shielding the G light charge accumulation unit 16, however,also function as a wiring, by being formed of conductive materials.

As the light shielding film 24, it is preferable to use a laminated filmof titanium (Ti) as barrier metal and titanium nitride (TiN) andtungsten (W), since it is necessary to make contact with the siliconsubstrate 11. The light shielding film 24 forms a contact unit(corresponds to contact units 33 and 34 in FIGS. 2 and 3) which makeselectrical contact with the silicon substrate 11 by being embedded inthe contact hole 23.

The light shielding film 24 is necessary to passes the input light withrespect to the B light photoelectric conversion layer 12 and the R lightphotoelectric conversion layer 15. Accordingly, an opening 24 _(O) isformed at the upper part of the photoelectric conversion layers 12 and15 of the light shielding film 24. The light shielding film 24 defines aregion where light in input to the silicon substrate 11 by the opening24 _(O).

An insulating film 25 is formed on the light shielding film 24, andfurther, a contact plug 26 is formed in pixel units through theinsulating film 25. The contact plug 26 makes electrical contact withrespect to the light shielding film 24 which is located at the upperpart of the G light charge accumulation unit 16. The top face of theinsulating film 25 is planarized by the CMP (Chemical MechanicalPolishing), or the like.

One electrode 27 (hereinafter, described as a “lower electrode”) whichis transparent is formed in pixel units on the insulating film 25. Thelower electrode 27 is formed in a state of being in electrical contactwith respect to the contact plug 26. An insulating film 28 formitigating the level difference of the edges of the lower electrode 27is formed at the periphery of the lower electrode 27. It is possible toform the insulating film 28 by performing etching so as to expose thefront surface of the lower electrode 27 with a taper shape, afterforming the insulating film across the entire surface.

The above described G light photoelectric conversion film 17 whichabsorbs the G light, and performs the photoelectric conversion is formedon the lower electrode 27 and the insulating film 28. The G lightphotoelectric conversion film 17 has an area which is larger than thearea (opening area) of the opening 24 _(O) of the light shielding film24. Further, a transparent electrode (hereinafter, described as an“upper electrode”) 29 as a part of the upper electrode is formed commonto all pixels, and over the entire pixel array unit (pixel region) whichis formed by the pixels which are arranged in a matrix, on thephotoelectric conversion film 17. Further, a transparent electrode 30 isformed on the upper electrode 29. The transparent electrode 30 iselectrically connected (comes into contact with) to a power supply unit31 in the silicon substrate 11 at the peripheral region of the pixelarray unit. In addition, a light shielding film 32 is formed on thepixels in an optical black region where the photoelectric conversion isnot performed.

The pixel structure of the above configuration has the lamination-typepixel structure in which the G light photoelectric conversion film 17 islocated outside the silicon substrate 11, and the B light photoelectricconversion unit 12 and the R light photoelectric conversion layer 15 arelaminated inside the silicon substrate 11. In addition, thelamination-type pixel structure adopts a backside illumination pixelstructure in which input light is radiated (incident) from the rearsurface 11 _(B) side of the silicon substrate 11.

In the lamination-type backside illumination pixel structure, apredetermined bias voltage is supplied to the transparent electrode 30through a part of the light shielding film 24 as the wiring from thepower supply unit 31 of the silicon substrate 11, and the bias voltageis supplied to the upper electrode 29 through the transparent electrode30. When light is input to the G light photoelectric conversion film 17through the transparent electrode 30 and the transparent upper electrode29, in a state where the bias voltage is applied to the upper electrode29, the photoelectric conversion film 17 absorbs the G light, andperforms the photoelectric conversion thereto.

The charge obtained due to the photoelectric conversion by the G lightphotoelectric conversion film 17 is taken out by the transparent lowerelectrode 27, is transferred to the G light charge accumulation unit 16through the contact plug 26, the light shielding film 24 (24 _(A)) asthe wiring, and further the contact unit 34 (refer to FIGS. 2 and 3),and is accumulated. The charge accumulated to the charge accumulationunit 16 is selectively transferred to an FD unit 18 by a control of thetransfer gate 19.

On the other hand, the light which has transmitted the G lightphotoelectric conversion film 17 is input to the silicon substrate 11through the opening 24 _(O) of the light shielding film 24.Subsequently, in a portion which is parallel to the substrate surface,that is, in the photoelectric conversion unit 12 _(A), the B lightphotoelectric conversion layer 12 absorbs the B light, and performs thephotoelectric conversion with respect to the B light, in the light inthe wavelength region other than G light, transfers the charge obtainedby the photoelectric conversion to a portion which is perpendicular tothe substrate surface, that is, the photoelectric conversion unit 12_(B), and accumulates the charge in the photoelectric conversion unit 12_(B). The charge accumulated in the B light charge accumulation unit 12_(A) is selectively transferred to the FD unit 13 by a control of thetransfer gate 14.

In addition, the light which has transmitted the B light photoelectricconversion layer 12 is input to the R light photoelectric conversionlayer 15. The R light photoelectric conversion layer 15 absorbs the Rlight, and performs the photoelectric conversion with respect to the Rlight, and accumulates the R light, in the light which has transmittedthe B light photoelectric conversion layer 12. Similarly to the chargewith respect to the G light and R light, the charge which is accumulatedin the R light photoelectric conversion layer 15 is also selectivelytransferred to the FD unit by a control of the transfer gate.

FIG. 2 is a top view in a state where the light shielding films 24 (24_(A) and 24 _(B)) of the pixel array unit in which the pixels arearranged in a matrix is formed. In addition, FIG. 3 enlarges four pixelsin FIG. 2 which are adjacent to each other vertically and horizontally.In FIGS. 2 and 3, the light shielding films 24 (24 _(A) and 24 _(B)) areshown by being hatched in order to facilitate understanding.

As shown in FIGS. 2 and 3, the light shielding film 24 is configured bythe light shielding film 24 _(A) which is formed in a lattice shapebetween pixels, and shields the pixels from each other, and the lightshielding film 24 _(B) which is formed in an island shape in the pixels,and shields the G light charge accumulation unit 16 of each pixel. Thelight shielding film 24 _(A) which shields the pixels from each other isformed in each pixel row and pixel column between pixels in the pixelarray unit, and is set to a predetermined potential, for example, a wellpotential (ground potential/0 V), by coming into contact with thesilicon substrate 11 through the contact unit 33 at the peripheralportion of the pixel array unit. That is, the light shielding film 24_(A) becomes equipotential in the entire region of the pixel array unit.

The light shielding film 24 _(A) not only performs shielding betweenpixels, but also performs shielding with respect to the chargeaccumulation unit (a portion perpendicular to the substrate surface) 12_(B) of the photoelectric conversion layer 12. Specifically, the lightshielding film 24 _(A) has a light shielding film 24 _(C) which isformed to be overhung to one corner portion of rectangular pixel in eachof pixels, and in the light shielding film 24 _(C), the photoelectricconversion unit 12 _(B) of the photoelectric conversion layer 12 isshielded.

On the other hand, the light shielding film 24 _(B) has an area which islarger than that of the upper part of the G light charge accumulationunit 16, and shields the G light charge accumulation unit 16 which isformed in an island shape in the rectangular pixel. In addition, thelight shielding film 24 _(B) functions as a wiring which transfers thecharge which is taken out by the lower electrode 27 to the G lightcharge accumulation unit 16 by being in contact with the siliconsubstrate 11 by the contact unit 34 of which a wiring material isembedded in the contact hole 23 (refer to FIG. 1).

In this manner, the charge of the light shielding film 24 _(B) whichshields the G light charge accumulation unit 16 is determined for eachpixel. In contrast to this, as described above, the light shielding film24 _(A) becomes equipotential, for example, the ground potential in theentire region of the pixel array unit. That is, the light shielding film24 _(A) which performing shielding between pixels and the lightshielding film 24 _(B) which shields the G light charge accumulationunit 16 for each pixel have different potentials from each other.

FIG. 4 shows a state where the transparent electrode 30 is added to theupper electrode 29 in laminating manner. As shown in the figure, thetransparent electrode 30 which is added to the upper electrode 29 inlaminating manner is electrically connected to the silicon substrate 11in the contact unit 35, in the peripheral portion of the pixel arrayunit, in order to make the potential same in the entire pixel withrespect to the upper electrode 29.

In this manner, as shown in FIG. 1, the upper electrode 29 has the samebias potential in the entire pixel, since a predetermined bias voltageis supplied to the upper electrode 29 through the contact unit 35 andtransparent electrode 30 from the power supply unit 31. Accordingly, itis possible to perform the photoelectric conversion by the G lightphotoelectric conversion film 17 under the same conditions in the entirepixel.

Manufacturing Process

Subsequently, the manufacturing process of the pixel structure accordingto the first example of the above configuration will be described usingFIGS. 4 to 9. In addition, in FIGS. 5 to 11, the same portions as thoseof FIG. 1 are provided with the same reference numerals. Further,similarly to the case in FIG. 1, the transfer gate of R light is notshown in the figure.

As shown in FIG. 5A, the B light and R light photoelectric conversionlayers 12 and 15 are laminated in the silicon substrate 11, and the Glight charge accumulation unit 16, the overflow barrier 20, and the N⁺contact unit 21 are formed, in a state where the silicon substrate 11 inwhich the wiring layer or the like is formed on the front surface 11_(A) side is turned inside out (first process).

Subsequently, as shown in FIG. 5B, an anti-reflection film 22 is formedon the rear surface (substrate surface) of the silicon substrate 11(second process), and then, as shown in FIG. 6A, the contact hole 23 isformed in the anti-reflection film 22 (third process). Here, thedistance between the light shielding film 24 and the substrate surfaceof the silicon substrate 11 is determined by the film thickness of theanti-reflection film 22. In addition, it is preferable to make the filmthickness of the anti-reflection film 22 as thin as possible, in orderto effectively suppress the light obliquely input, since the lightshielding film 24 is formed in a state of being adjacent to thesubstrate surface of the silicon substrate 11.

Subsequently, as shown in FIG. 6B, a conductive film 240 as the lightshielding film 24 which also serves as the wiring is formed on theanti-reflection film 22, and the conductive film 240 is embedded in thecontact hole 23 (fourth process). It is preferable to use a laminatedfilm of titanium (Ti) as barrier metal and titanium nitride (TiN) andtungsten (W) for the conductive film 240, since it is necessary to makecontact with the silicon substrate 11.

Subsequently, as shown in FIG. 7A, conductive film 240, that is, Ti,TiN, and W are processed so as to remain only in the portion for whichshielding is desired (fifth process). Here, it is possible to form theplug and the light shielding film 24 without increasing the number ofprocesses, by remaining the material of the contact plug as is as thelight shielding film 24.

Subsequently, as shown in FIG. 7B, the insulating film 25 is formed onthe shielding film 24, and the top face of the insulating film 25 isplanarized using, for example, CMP (Chemical Mechanical Polishing)(sixth processing). In addition, as shown in FIG. 8A, the contact plug26 is formed on the light shielding film 24 (seventh processing), andthen, as shown in FIG. 8B, a transparent electrode as the lowerelectrode 27 of the G light photoelectric conversion film 17 is formed(eighth processing).

Subsequently, as shown in FIG. 9, the insulating film 28 for mitigatingthe level difference of the edges of the lower electrode 27 is formed(ninth processing). It is possible to form the insulating film 28 byperforming etching so as to expose the front surface of the lowerelectrode 27 with a taper shape, after entirely forming the insulatingfilm.

Subsequently, as shown in FIG. 10, the G light photoelectric conversionfilm 17 and the transparent electrode as a part of the upper electrode29 are sequentially formed (tenth processing). Here, after forming the Glight photoelectric conversion film 17 and the transparent electrode asa part of the upper electrode 29, the photoelectric conversion film 17is processed so as to be the desired shape having the upper electrode 29as a hard mask. Thereafter, as shown in FIG. 11, the transparentelectrode 30 is further added by being laminated (eleventh processing).In addition, as shown in FIG. 1, finally, the light shielding film 32 isformed on the pixel in the optical black region in which thephotoelectric conversion is not performed.

As described above, the pixel structure according to the first exampleadopts the backside illumination pixel structure. According to thebackside illumination pixel structure, since the wiring layer is notpresent between the silicon substrate 11 and the G light photoelectricconversion film 17, it is possible to make the distance short betweenthe photoelectric conversion film 17 and the substrate surface, andbetween the photoelectric conversion film 17 and the photoelectricconversion layers 12 and 15 inside the substrate compared to the pixelstructure of the front side illumination in which the wiring layer ispresent. Due to this, it is possible to reduce the F value dependencyfor the sensitivity of each color, since the change in sensitivity withrespect to the F value which is caused by a difference in arrangementposition of the G light photoelectric conversion film 17 and the B lightand R light photoelectric conversion layers 12 and 15 in the opticalaxis direction of the input light can be reduced.

Here, when the B light and R light photoelectric conversion layers 12and 15 are provided in the silicon substrate 11, it is necessary to openthe light receiving surface of the silicon substrate 11, that is, theupper portions of the photoelectric conversion layers 12 and 15. Inaddition, similarly, it is necessary to shield the G light chargeaccumulation unit 16 which is provided in the silicon substrate 11, andit is desired to reliably suppress the leakage of light which is inputobliquely with respect to the light shielding film 24.

In contrast to this, in the pixel structure according to the firstexample, it has a structure in which the shielding is performed at aposition adjacent to the substrate surface, since only theanti-reflection film 22 is present between the light shielding films 24(24 _(A), 24 _(B), and 24 _(C)) and the silicon substrate 11.Accordingly, it is possible to reliably suppress the leakage of lightwhich is input obliquely by the light shielding film 24, even though theopening 24 _(O) is present in the light shielding film 24. In addition,it is possible to further reliably suppress the leakage of obliquelight, since the light shielding film 24 also functions as the wiring,and the contact portion which electrically connects the G lightphotoelectric conversion film 17 and the silicon substrate 11 to eachother, that is, a convex portion which protrudes to the substrate sideof the light shielding film 24 also forms a part of the light shieldingstructure of the G light photoelectric conversion film 17.

In addition, even in the two photoelectric conversion layers 12 and 15which are provided in the silicon substrate 11, it is necessary toperform shielding between pixels which are adjacent to each other inorder to suppress the color mixing between adjacent pixels. Even forthis, in the pixel structure according to the first example, the lightshielding film 24 _(A) which shields the adjacent pixels is formed inthe same process, and as the same layer as the light shielding film 24_(B) which shields the G light charge accumulation unit 16, accordingly,it is possible to perform desired shielding without increasing thenumber of processes. Due to this, it is possible to exert an effect ofreducing the color mixing between pixels.

In addition, further, it is necessary to apply a predetermined biasvoltage to the upper electrode 29 in order to perform the photoelectricconversion in the photoelectric conversion film 17 which is formed bybeing pinched by the lower electrode 27 and the upper electrode 29. Incontrast to this, in the pixel structure according to the first example,since the light shielding film 24 is used as a part of the wiring forapplying the predetermined bias voltage to the upper electrode 29, it ispossible to suppress an increase in the number of processes compared toa case of forming a separate wiring.

1-2. Second Example

A pixel structure according to a second example has the same pixelstructure according to the first example, basically, in the structureand the flow of processing, however, a configuration of a lightshielding film 24 and the way of taking a potential are different fromthe pixel structure according to the first example. That is, in thecross-section structure of the pixel structure according to the secondexample, the structure is basically the same as the pixel structureaccording to the first example shown in FIG. 1 excluding theconfiguration of the light shielding film 24.

FIG. 12 is a top view in a state where the light shielding film 24 of apixel array unit in the pixel structure according to the second exampleof the solid-state imaging device according to the embodiment of thepresent disclosure is formed. In addition, FIG. 13 enlarges four pixelsin FIG. 12 which are adjacent to each other vertically and horizontally.In FIGS. 12 and 13, the light shielding film 24 is shown by beinghatched in order to facilitate understanding.

In the pixel structure according to the first example has aconfiguration in which the entire peripheral portion of the pixel isshielded by the light shielding film 24 (24 _(A)and 24 _(C)), and a Glight charge accumulation unit 16 is shielded by the light shieldingfilm 24 _(B) which is electrically separated from the light shieldingfilm 24. In addition, the light shielding film 24 comes into contactwith, for example, a ground potential in a contact unit 33 in theperiphery of a pixel array unit, and the light shielding film 24 _(B)functions as a wiring, as well, by coming into contact with a siliconsubstrate 11 in a contact unit 34.

In contrast to this, as shown in FIGS. 12 and 13, the pixel structureaccording to the second example has a configuration in which the lightshielding film 24 _(B) which shields the G light charge accumulationunit 16 as the light shielding film 24, and a light shielding film 24_(C) which shields the photoelectric conversion unit 12 _(B) of the Blight photoelectric conversion layer 12 are integrally formed. As amatter of course, an opening 24 _(O) which passes input light is formedat the upper portion of the photoelectric conversion unit 12 _(A) of theB light photoelectric conversion layer 12, in the light shielding film24.

In addition, the light shielding films 24 (24 _(B) and 24 _(C)) alsofunction as wirings which supply a charge which is taken out from aphotoelectric conversion film 17 through a lower electrode 27 to the Glight charge accumulation unit 16, by coming into contact with thesilicon substrate 11 in the contact unit 34. The light shielding films24 (24 _(B) and 24 _(C)) have structures which are separated from eachother in each pixel, since they are forming a part of the wiring.

FIG. 14 shows a state where a transparent electrode 30 is added to anupper electrode 29 by being laminated. As shown in the figure, thetransparent electrode 30 which is added to the upper electrode 29 bybeing laminated is electrically connected to the silicon substrate 11 inthe contact unit 35 at the peripheral portion of the pixel array unit,in order to have the same potential in the entire pixel with respect tothe upper electrode 29.

According to the pixel structure in the second example, the lightshielding film 24 _(C) which shields the photoelectric conversion unit12 _(B) of the B light photoelectric conversion layer 12 and the lightshielding film 24 _(B) which shields the G light charge accumulationunit 16 are integrally formed, it is possible to eliminate light leakagefrom the upper portion between the photoelectric conversion unit 12 _(B)and the charge accumulation unit 16. In addition, since the contactportion which corresponds to the contact portion 33 in FIG. 2 is notnecessary, it is possible to reduce the chip size by the number ofcontact portions decreased.

1-3. Third Example

A pixel structure according to a third example is basically the same asthe pixel structure in the first example regarding the structure and theprocess, however, a configuration of a light shielding film 24 and theway of taking a potential are different from the pixel structureaccording to the first example. That is, in the cross-section structureof the pixel structure according to the third example, the structure isbasically the same as the pixel structure according to the first exampleshown in FIG. 1, excluding the configuration of the light shielding film24.

FIG. 15 is a top view in a state where the light shielding film 24 of apixel array unit in the pixel structure according to the third exampleof the solid-state imaging device according to the embodiment of thepresent disclosure is formed. FIG. 16 enlarges four pixels in FIG. 15which are adjacent to each other vertically and horizontally. In FIGS.15 and 16, the light shielding film 24 is shown by being hatched inorder to facilitate understanding.

In the pixel structure according to the second example, a lightshielding film 24 _(B) which shields a G light charge accumulation unit16 as the light shielding film 24, and a light shielding film 24 _(C)which shields a photoelectric conversion unit 12 _(B) of the B lightphotoelectric conversion layer 12 are integrally formed. In addition, ithas a configuration in which the light shielding film 24 _(A) of alattice shape between pixels in the pixel structure in the first exampleis omitted.

In contrast to this, similarly to a case of the pixel structure in thesecond example, the pixel structure according to the third example has aconfiguration in which the light shielding film 24 _(B) which shieldsthe G light charge accumulation unit 16, and a light shielding film 24_(C) which shields the photoelectric conversion unit 12 _(B) of thephotoelectric conversion layer 12 are integrally formed, for example, inan L shape. An opening 24 _(O) which passes input light is formed at theupper portion of the photoelectric conversion unit 12 _(A) of the Blight photoelectric conversion layer 12, in the light shielding films 24(24 _(B) and 24 _(C)).

In addition, in the pixel structure according to the third example, asshown in FIGS. 15 and 16, it has a configuration in which the lightshielding film 24 _(A) which is formed in the lattice shape betweenpixels, and shields between pixels is provided, similarly to a case ofthe pixel structure in the first example. The light shielding film 24_(A) is set to a well potential, for example, a ground potential (0 V)by being in contact with the silicon substrate 11 through the contactunit 33 in the peripheral portion of the pixel array unit. That is, thelight shielding film 24 _(A) becomes equipotential in the entire regionof the pixel array unit.

FIG. 17 shows a state where a transparent electrode 30 is added to anupper electrode 29 by being laminated. As shown in the figure, thetransparent electrode 30 which is added to the upper electrode 29 bybeing laminated is electrically connected to the silicon substrate 11 inthe contact unit 35 at the peripheral portion of the pixel array unit,in order to have the same potential in the entire pixel with respect tothe upper electrode 29.

1-4. Fourth Example

FIG. 18 is a cross-sectional view which shows a pixel structureaccording to a fourth example of the solid-state imaging device in theembodiment of the present disclosure, and the same portions in thefigure as those in FIG. 1 are provided with the same reference numerals.

In the pixel structure according to the fourth example, the structureand the flow of processing is basically the same as that in the pixelstructure according to the first example, however, a configuration of anN⁺ contact unit 21 and a light shielding film 24 are different from thepixel structure according to the first example. That is, in thecross-section structure of the pixel structure according to the fourthexample, the structure is basically the same as the pixel structureaccording to the first example shown in FIG. 1, excluding theconfiguration of the N⁺ contact unit 21, and the light shielding film24.

In the pixel structure according to the first example, the N⁺ contactunit 21 is formed in an area with approximately the same size as that ofthe G light charge accumulation unit 16 when planarly viewed (whenviewed from a light input surface), and a contact hole 23 is formed in ahole diameter corresponding to the size of the contact unit 21. Due tothis, the area of the bottom portion of the contact hole 23 of the lightshielding unit 24 is considerably small compared to the area of theupper portion of the G light charge accumulation unit 16.

In contrast to this, the pixel structure according to the fourth exampleforms the N⁺ contact unit 21 in an area which is larger than that of theG light charge accumulation unit 16 when planarly viewed (when viewedfrom a light input surface), and has a structure in which the contacthole 23 is formed with a hole diameter larger in size than the region ofthe charge accumulation unit 16 to the extent that it does not protrudefrom the region of the contact unit 21. In addition, it is possible toform the light shielding film 24 (24 _(A) and 24 _(B)) which alsofunctions as the wiring, by embedding a conductive material in thecontact hole 23.

As described in the first example, as well, the light shielding film 24_(A) is a light shielding film which shields between pixels by beingformed in a lattice shape between the pixels. In addition, the lightshielding film 24 _(B) is a light shielding film which shields the Glight charge accumulation unit 16 of each pixel which is formed in anisland shape in the pixels.

In the pixel structure according to the fourth example, the bottomportion of the contact hole 23 of the light shielding unit 24 has alarge area compared to a case of the pixel structure according to thefirst example, and not only performs an electrical connection to the N⁺contact unit 21, but also functions as the light shielding film. In thismanner, it is possible to effectively prevent oblique input light fromleaking into the G light charge accumulation unit 16, since the distancebetween the G light charge accumulation unit 16 and the light shieldingfilm 24 (that is, the bottom portion of the contact hole 23 of the lightshielding unit 24).

In addition, in the pixel structure according to the fourth example, itcan be also mentioned as one of characteristics that the contact hole 23is formed with a hole diameter smaller than the region of the N⁺ contactunit 21. When the contact hole 23 is formed so as to protrude from theregion of the N⁺ contact unit 21, the leakage is increased throughcontact metal between the N⁺ contact unit 21 and P well (substrate) atthe periphery of the N⁺ contact unit 21. Accordingly, it is important tomake the region of the contact hole 23 smaller than that of the N⁺contact unit 21.

In addition, a structure in which the region of the contact hole 23 isformed to be smaller than that of the N⁺ contact unit 21, and furtherthe G light charge accumulation unit 16 is shielded at the bottomportion of the contact hole 23 of the light shielding unit 24 is astructure which can be realized only by the pixel structure according tothe fourth example (first example). Specifically, it is an advantageousstructure which is possible only because the G light charge accumulationunit 16, the overflow barrier 20, and the N⁺ contact unit 21 arelaminated in the vertical direction (direction perpendicular to thesubstrate surface).

In other words, the pixel structure according to the fourth example isnot realized in a structure in which the overflow barrier 20 is formednext to the N⁺ contact unit 21, and the G light charge accumulation unit16 is formed in the horizontal direction (direction parallel to thesubstrate surface).

2. Modification Example

In the above described embodiment, a pixel structure was described as anexample in which the photoelectric conversion film which is providedoutside the substrate is set to the G light photoelectric conversionfilm, and the photoelectric conversion layer which is provided insidethe substrate is set to the photoelectric conversion layers of B lightand R light, however, this combination is only an example, and is notlimited thereto.

That is, the photoelectric conversion film which is provided outside thesubstrate may be a film which performs the photoelectric conversion withrespect to light in a predetermined wavelength region, and transmitslight in other wavelength regions. In addition, the photoelectricconversion layer which is provided inside the substrate may be a layerwhich performs the photoelectric conversion with respect to light inother wavelength regions.

In addition, in the above embodiment, a pixel structure was described asan example, in which photoelectric conversion layer which is provided inthe substrate is set to two colors of photoelectric conversion layers ofB light and R light, however, the structure is not limited thereto, andit is possible to apply the technology of the present disclosure, whenit is a pixel structure in which at least one color of photoelectricconversion layer is provided in the substrate.

In addition, the technology of the present disclosure is not onlyapplied to a solid-state imaging device which detects the distributionof the light intensity of input visible light, and performs imaging asan image, but is also applicable to all solid-state imaging deviceswhich image the distribution of the input amount of infrared light,X-rays, or particles or the like as an image.

In addition, the solid-state imaging device may be formed as one chip,or may be a modular form with an imaging function in which an imagingunit and a signal processing unit, or an optical system are integrallypackaged.

3. Electronic Apparatus

The present disclosure is applied not only to the solid-state imagingdevice, but also to all electronic apparatuses in which the solid-stateimaging device is used in the imaging unit (photoelectric conversionunit) such as an imaging device like a digital still camera, a videocamera, or the like, and a mobile terminal device having an imagingfunction such as a mobile phone. In the electronic apparatus in whichthe solid-state imaging device is used in the imaging unit, a copymachine which uses the solid-state imaging device in the image readingunit is also included. In addition, there is a case where the modularform which is installed to the electronic apparatus, that is, the cameramodule is used as the imaging device.

Imaging Device

FIG. 19 is a block diagram which shows an example of a configuration ofthe electronic apparatus according to the present disclosure, forexample, the imaging device.

As shown in FIG. 19, the imaging device 100 according to the presentdisclosure includes an optical system including such as a lens group 101or the like, an imaging element (imaging device 102), a DSP circuit 103,a frame memory 104, a display device 105, a recording device 106, anoperation system 107, a power supply system 108, or the like. Inaddition, the DSP circuit 103, the frame memory 104, the display device105, the recording device 106, the operation system 107, and the powersupply system 108 are connected to each other through a bus line 109.

The lens group 101 takes in input light (image light) from an object,and forms as an image on the imaging surface of the imaging element 102.The imaging element 102 converts the intensity of the input light whichis imaged on the imaging surface by the lens group 101, and outputs aspixel signals.

The display device 105 is formed of a panel-type display device such asa liquid display device, or an organic EL (electro luminescence) displaydevice or the like, and displays a moving image, or a still image whichis incident the imaging element 102. The recording device 106 records amoving image or a still image which is incident the imaging element 102on a recording medium such as a video tape, a DVD (Digital VersatileDisc), or the like.

The operation system 107 issues an operating instruction with respect toa variety of functions which is included in the imaging device under theoperation by a user. The power supply system 108 appropriately suppliesvarious types of power supply as an operation power source of the DSPcircuit 103, the frame memory 104, the display device 105, the recordingdevice 106, and the operation system 107 to these supply targets.

The imaging device with the configuration is able to be used as a videocamera, or a video still camera, and further, as a variety of imagingdevices such as a camera module for mobile devices such as a mobilephone. In addition, in the imaging device, it is possible to obtain thefollowing operation and effect, by using the solid-state imaging deviceaccording to the above described embodiments as the imaging unit, thatis, as the imaging element 102.

That is, the solid-state imaging device according to the above describedembodiments is able to reduce the F value dependency of the sensitivityof each color, since it is possible to make the change in sensitivitywith respect to the F value which is caused by the difference inarranging position of the photoelectric conversion film and thephotoelectric conversion layer, in the optical axis direction of theinput light. Accordingly, it is possible to obtain a good captured imageby using the solid-state imaging device as the imaging unit in thevariety of imaging devices.

4. Configuration of the Present Disclosure

(1) A solid-state imaging device which includes, a photoelectricconversion film provided on a second surface side which is the oppositeside to a first surface on which a wiring layer of a semiconductorsubstrate is formed, performs photoelectric conversion with respect tolight in a predetermined wavelength region, and transmits light in otherwavelength regions; and a photoelectric conversion layer which isprovided in the semiconductor substrate, and performs the photoelectricconversion with respect to light in other wavelength regions which hastransmitted the photoelectric conversion film, in which input light isincident from the second surface side with respect to the photoelectricconversion film and the photoelectric conversion layer.

(2) The solid-state imaging device described in (1) includes a lightshielding film which defines a region in which light is input to thesemiconductor substrate, in which the light shielding film iselectrically connected to the semiconductor substrate.

(3) The solid-state imaging device described in (2), in which the lightshielding film is provided with an opening which passes input light tothe semiconductor substrate side, and the photoelectric conversion filmhas an area which is larger than that of the opening.

(4) The solid-state imaging device described in any one of (2) or (3),further includes a charge accumulation unit which is provided in thesemiconductor substrate, and accumulates a charge which isphotoelectrically converted in the photoelectric conversion film, inwhich the light shielding film is electrically connected to thesemiconductor substrate for each pixel, and transfers the charge whichis photoelectrically converted in the photoelectric conversion film tothe charge accumulation unit.

(5) The solid-state imaging device described in (4), in which the lightshielding film has an area which is larger than that of an upper portionof the charge accumulation unit, and performs light shielding withrespect to the charge accumulation unit.

(6) The solid-state imaging device described in (5), in which the lightshielding film includes a convex portion which protrudes from a portionwhich has a larger area than that of the charge accumulation unit, and aportion of the large area to the semiconductor substrate side, and comesinto electrical contact with a diffused region which is formed on afront layer portion of the semiconductor substrate, in which lightshielding is performed with respect to the charge accumulation unit evenby the convex portion.

(7) The solid-state imaging device described in (5), in which the lightshielding film comes into electrical contact with the diffused regionwhich is formed on the front layer portion of the semiconductorsubstrate, and the diffused region has a large area than that of theupper portion of the charge accumulation unit.

(8) The solid-state imaging device described in any of (2) to (7), inwhich the light shielding film has a light shielding region whichperforms the light shielding between pixels, and the light shieldingregion is applied with a predetermined potential from the semiconductorsubstrate side through the light shielding film.

(9) The solid-state imaging device described in any of (2) to (7), inwhich the photoelectric conversion film is pinched by a lower electrodeand an upper electrode, and a part of the light shielding film is usedas a wiring which supplies a predetermined bias voltage to the upperelectrode from the semiconductor substrate side.

(10) An electronic apparatus which includes a solid-state imaging deviceincluding, a photoelectric conversion film provided on a second surfaceside which is the opposite side to a first surface on which a wiringlayer of a semiconductor substrate is formed, performs photoelectricconversion with respect to light in a predetermined wavelength region,and transmits light in other wavelength regions; and a photoelectricconversion layer which is provided in the semiconductor substrate, andperforms the photoelectric conversion with respect to light in otherwavelength regions which has transmitted the photoelectric conversionfilm, and in which input light is incident from the second surface sidewith respect to the photoelectric conversion film and the photoelectricconversion layer.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. An imaging device comprising: a substrate havinga first side and a second side as a light incident side, the substrateincluding: a first photoelectric conversion unit, and a secondphotoelectric conversion unit; a wiring layer disposed adjacent to thefirst side of the substrate; and a photoelectric conversion filmdisposed over the second side of the substrate, wherein, at least aportion of the second photoelectric conversion unit is disposed betweenthe first photoelectric conversion unit and the photoelectric conversionfilm, and the photoelectric conversion film is an organic film.
 2. Theimaging device according to claim 1, further comprising: a lowerelectrode; and an upper electrode, wherein the photoelectric conversionfilm is located between the lower electrode and the upper electrode. 3.The imaging device according to claim 2, further comprising: aninsulating film located between the second side of the substrate and thelower electrode, wherein a portion of the photoelectric conversion filmis disposed on the insulating film.
 4. The imaging device according toclaim 3, wherein a portion of the photoelectric conversion film isdisposed on the lower electrode.
 5. The imaging device according toclaim 4, wherein the lower electrode is formed in pixel units.
 6. Theimaging device according to claim 5, wherein the upper electrode iscommon to a plurality of pixels.
 7. The imaging device according toclaim 6, further comprising: a transparent electrode formed on the upperelectrode, wherein the transparent electrode is electrically connectedto the substrate via at least one contact unit.
 8. The imaging deviceaccording to claim 7, further comprising: a pixel array including theplurality of pixels, wherein the at least one contact unit is located ina peripheral portion of the pixel array.
 9. The imaging device accordingto claim 2, further comprising: a floating diffusion region; and a lightshielding film located between the photoelectric conversion film and thesecond side of the substrate, wherein charge is transferred from thephotoelectric conversion film to the floating diffusion region via thelight shielding film.
 10. The imaging device according to claim 9,wherein the light shielding film includes at least one of Ti, TiN, or W.11. The imaging device according to claim 9, further comprising: a pixelarray including a plurality of pixels, wherein the light shielding filmis located between adjacent pixels in the pixel array, and wherein thelight shielding film is set to a predetermined potential.
 12. Theimaging device according to claim 9, further comprising: another lightshielding film formed on the transparent electrode in an optical blackregion in which photoelectric conversion is not performed.
 13. Theimaging device according to claim 2, further comprising: an electrodedisposed on the upper electrode; and a power supply unit, wherein theelectrode is electrically connected to the power supply unit.
 14. Theimaging device according to claim 2, further comprising: a power supplyunit electrically connected to the upper electrode.
 15. The imagingdevice according to claim 2, wherein the upper electrode is transparent.16. The imaging device according to claim 2, wherein the lower electrodeis transparent.
 17. The imaging device according to claim 2, furthercomprising: an insulating film disposed at edges of the lower electrode.18. The imaging device according to claim 1, wherein the photoelectricconversion film is common to a plurality of pixels.
 19. The imagingdevice according to claim 1, wherein the photoelectric conversion filmis sensitive to green light.
 20. The imaging device according to claim1, wherein the first photoelectric conversion unit is sensitive to redlight.
 21. The imaging device according to claim 1, wherein the secondphotoelectric conversion unit is sensitive to blue light.
 22. Theimaging device according to claim 1, wherein the first and secondphotoelectric conversion units are sensitive to a same color of light.23. The imaging device according to claim 1, wherein the secondphotoelectric conversion unit corresponds to a portion of aphotoelectric conversion layer that is parallel to a surface of thesubstrate, and the first photoelectric conversion unit corresponds to aportion of the photoelectric conversion layer that is perpendicular tothe surface of the substrate.
 24. The imaging device according to claim1, further comprising: a light shielding film located between thephotoelectric conversion film and the second side of the substrate,wherein the light shielding film includes an opening which passes lightto the second side, and wherein an area of the photoelectric conversionfilm is larger than an area of the opening.
 25. The imaging deviceaccording to claim 1, further comprising: an electrode, wherein theelectrode is electrically connected to the photoelectric conversionfilm.
 26. The imaging device according to claim 25, wherein theelectrode is a transparent electrode.
 27. The imaging device accordingto claim 1, wherein the photoelectric conversion film is sensitive togreen light, the first photoelectric conversion unit is sensitive to redlight, and the second photoelectric conversion unit is sensitive to bluelight.
 28. The imaging device according to claim 1, further comprising:a transfer gate that is configured to transfer charge from thephotoelectric conversion film to a floating diffusion region.
 29. Theimaging device according to claim 1, further comprising: a chargeaccumulation unit configured to accumulate charge from the photoelectricconversion film, wherein charge is transferred from the photoelectricconversion film to the charge accumulation unit via a conductivematerial embedded in a contact hole.
 30. An electronic apparatus,comprising: an imaging device including: a substrate having a first sideand a second side as a light incident side, the substrate including: afirst photoelectric conversion unit, and a second photoelectricconversion unit, a wiring layer disposed adjacent to the first side ofthe substrate, and a photoelectric conversion film disposed over thesecond side of the substrate, wherein, at least a portion of the secondphotoelectric conversion unit is disposed between the firstphotoelectric conversion unit and the photoelectric conversion film, andthe photoelectric conversion film is an organic film; and an opticalsystem that forms an image on the light incident side of the imagingdevice.